Train identity control system

ABSTRACT

A selectively tuned train coil is provided for each digit of a train&#39;&#39;s identity number, mounted to successively couple, in descending digit order, with coils of the wayside receiving apparatus. Each digit successively received by the wayside apparatus is immediately translated from decimal to a two-out-offive code format and temporarily registered in a separate bank of code bit relays. This identity code is transmitted to a remote location including a route type interlocking control system. Each identity code is received and cascaded through a series of relay storage banks, reaching the final bank when the corresponding train is next to arrive at the interlocking. The code readout circuit network, which automatically selects the desired route control relay, includes a code format checking matrix, to assure that two but only two bits are actually registered for each identity digit, and a translation matrix to reconvert the unit digit code to decimal form.

United States Patent Elcan et al.

[54] TRAIN IDENTITY CONTROL SYSTEM [72] Inventors: Joel E. Elcan,Monroeville; Arthur Paul Jackel, Penn Hills Township, Allegheny County,both of Pa.

[73] Assignee: Westinghouse Air Brake Company, Swissvale, Pa.

[22] Filed: Apr. 9, 1970 [21] Appl.No.: 26,884

Pearce, Common Control ofTelephone Systems Chapter 4 (Circuits), 1967 51May 9, 1972 Primary Examiner-Arthur L. La Point Assistant ExaminerGeorgeH. Libman Att0rney-H. A. Williamson, A. G. Williamson, Jr. and J. B.Sotak [5 7] ABSTRACT A selectively tuned train coil is provided for eachdigit of a trains identity number, mounted to successively couple, indescending digit order, with coils of the wayside receiving apparatus.Each digit successively received by the wayside apparatus is immediatelytranslated from decimal to a two-outof-five code format and temporarilyregistered in a separate bank of code bit relays. This identity code istransmitted to a remote location including a route type interlockingcontrol system. Each identity code is received and cascaded through aseries of relay storage banks, reaching the final bank when thecorresponding train is next to arrive at the interlocking. The codereadout circuit network, which automatically selects the desired routecontrol relay, includes a code format checking matrix, to assure thattwo but only two bits are actually registered for each identity digit,and a translation matrix to reconvert the unit digit code to decimalform.

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PATENTEDMAY 9 I972 SHEET 5 [IF 5 i TIIZ 1 ffl iid w" P- JacKel m M m mmm my 6% Q mi w? @v m \w m N m w k a E E k E k E TRAIN IDENTITY CONTROLSYSTEM Our invention pertains to a train identity control system. Moreparticularly, the invention is directed to a control system by which acontrollable function located along the wayside of a railroad track iscontrolled in accordance with a function control signal, normally in theform of a train identity signal, transmitted from a train and registeredat a wayside point remote from the control function location.

In the initial design or the improvement of rapid transit and commuterrailroad systems, a principal goal is to increase the average speed ofthe trains and thereby increase the passenger carrying capacity of theoverall system. One manner in which this goal may be achieved is thereduction of train delays at stations, at interlockings, and at otherlocations where any other type control function is exercised over themovement of the train and at which trains frequently encounter delays.For example, passengers on a station platform may not be ready toimmediately board the train because they lack knowledge as to thedestination or class of the arriving train. In another instance, theoperator at an interlocking can not accomplish quickly enough therequired actions to manually select and thus set up the routes for eachtrain when such trains arrive along one or several approach routes withclose headway, that is, with close time spacing between the trains. Ifadvance notice can be given to the passengers so that they may be readyto board the desired train when it arrives, less station dwell time willoccur. For example, if a controlled display may be provided showing theidentity of an approaching train, passengers will be aware of itsdestination and whether or not they desire to board the train. A similartype display will aid the interlocking operator in deciding on thenecessary routes and in his preparation for selecting such routes. Theautomatic selection and control of the routes within the interlocking iseven better. This last feature requires that the train identity beforwarded to the interlocking control system to select and initiate theestablishment of the proper route, when wayside conditions are safe forsuch operations, while the train is approaching. In other words, thetrain identity signal must be registered as a function control signal atsome location in the approach in the interlocking, the signal beingfirst transmitted from train carried apparatus to wayside apparatus, andthen transmitted forward to actuate the selection and control operationfor the interlocking arrangement.

Accordingly, an object of our invention is a train identity controlsystem for transmitting a control function signal from a train towayside apparatus to actuate a controllable function located at somepoint along the railroad track traversed by that train.

Another object of the invention is a train identification system inwhich a multi-digit identity signal is transmitted from the trainapparatus to a wayside receiver.

A further object of the invention is an arrangement for controlling afunction along the track wayside by a control signal received from anapproaching train.

Still another object of the invention is a multi-digit trainidentification system using one coil mounted on the train for each digitand successively receiving and registering the digits of the identitysignal as that train passes a wayside receiver.

It is also an object of the invention to provide a multi-digit trainidentification system using one tuned coil mounted on the train for eachdigit to successively actuate wayside receiver apparatus to register thetrain identity signal for use in controlling a wayside function inadvance along the route for that train.

A still further object is a function control arrangement for a railroadsystem in which a multi-digit train identification signal, transmittedsuccessively digit by digit from the train to wayside receiver-registryapparatus, is used to actuate the operation of a controlled waysidefunction in advance along the route of the train.

Yet another object of our invention is automatic route selectionapparatus in which a multi-digit train identity signal, received andregistered by wayside apparatus one digit at a time as the train passesan identification point, is transferred by a communication means tostorage banks and then extracted to select the proper route through aninterlocking as the corresponding train approaches that location.

Other objects, features, and advantages of our invention will becomeapparent from the following specification when taken in connection withthe accompanying drawings and claims.

In practicing our invention, each train is provided with one tuned coilfor each digit of the multi-digit train identity number, herein shown asbeing two digits. Specifically shown and preferably, the coilrepresenting the higher digit, that is, the tens digit, precedes thelower or units digit coil as the train moves along the track. However,the reverse positioning of such coils may be selected and the registryof such digit arrangement is within the scope of our system. The tuningof these train marker coils is selected by the train operator or othersat the origin of the train, using an identity selector device hereinshown as a switch for each coil, in accordance with the train class, itsroute, type of train, or other identifying characteristics. At thewayside location for registering the identification, apparatusresponsive to the passage of the train coils to detect the specificcharacteristic signal, i. e., frequency tuning, of each coil, is mountedin a position along the track appropriate for the mounting point of thecoils on the train. This wayside apparatus responds to separatelyregister the digit numbers represented by the frequency tuning of eachcoil. In other words, passage of the first train coil by the waysidepoint actuates the registry, in accordance with the tuned frequencysignal of that coil, of the higher or tens digit of the train number.Passage of the second coil actuates the registration of the units digitnumber. This two digit train identity number is temporarily registeredin a relay bank in decimal form in successive digit order in accordancewith the passage of the coils. A stepping apparatus arrangement assuresthat the temporary registry of each coil signal is properly identifiedwith its digit position. Further, in order to conveniently servecommunication requirements, the decimal registration is immediatelyconverted into a selected code form. In the specific illustration, wehave chosen a two-out-of-five bits code format (hereinafter usuallydesignated 2/5 code), which is well known in the communication art. Thetranslation is done digit by digit through circuitry including a diodematrix. Each digit of the train number thus specifically requires fivebit relays in order to register the two-out-of-five code. A display ofthe registered train identity at this registry location may be provided,as specifically shown herein by banks of lights, a separate bank beingprovided for each digit with one light for each decimal number.

To provide a useful operation such as the control of a wayside functionin advance of the train, the registered train identity code istransmitted to such an advance location. As specifically shown, thecontrollable function comprises the route selection function in a routetype interlocking control system. This route selection in turn actuatesthe interlocking control system to establish the selected route. Thetrain identity is transferred as soon as all the digits are registeredin the 2/5 code form. This transmission is over a communicationchannelto a similar bank of bit relays at the advance location, againfive relays for each digit of the train number. For convenience, as willbe later discussed, the communication channel is shown as a cable, butother forms of communication means using other types of transmission maybe used as desired. From the advance location bit relay bank, the trainidentity signal is transferred into an initial storage relay bank usingthe same two-out-five code format. The identity storage is held in theinitial bank until a storage space is available in successive banks ofthe apparatus. The number of storage banks provided assures that theinitial bank will always be available for a newly registered trainidentity. In other words, the number of banks used will be in accordancewith the maximum number of trains which may possibly occupy the stretchof track between the identity registry location and the location of thefunction to be controlled. As succeeding ones of the storage banksbecome available, this train identity code storage is transferredforward. For simplicity, we specifically show only two banks. In thefinal storage bank, the stored identity code is checked for accuracy,decoded, and then used to select the desired route for the correspondingtrain. The selected route is established by conventional routeinterlocking control apparatus, in such manner that the desired route isprepared when the train arrives.

We will now describe the arrangement embodying our invention in greaterdetail with reference to the accompanying drawings in which:

FIG. I is a schematic block diagram and flow chart illustrating theoverall concept of the system embodying our invention.

FIG. 1A is a schematic illustration of one possible arrangement forselecting the characteristic tuning for each train coil.

FIG. 2 provides a chart to illustrate the physical arrangement of FIGS.3 to 6 necessary to properly connect the detailed circuitry of oursystem.

FIGS. 3, 4, 5, and 6, when arranged as illustrated in FIG. 2, show adetailed schematic circuit diagram illustrating one form of the trainidentity control system embodying the principles of our invention.

In each of the drawings, similar references refer to similar parts ofthe apparatus. Also in the drawings, a direct current source of energyis assumed for supplying such energy for operation of the variousrelays. A specific source is not shown since the use of such isconventional and any type known in the art which provides the necessaryvoltage and capacity may be used. For convenience, connections to thepositive and negative terminals of this direct current source aredesignated by the reference characters B and N, respectively.

Referring now to F IG. 1, across the top is shown, by conventionalsymbols, a stretch of railroad track. Trains normally move from left toright along this stretch to approach the interlocking shown at the rightwhere three routes are available, completed over the conventionallyshown track switches to tracks TE, TF, and TG. At the left of thefigure, remote from the interlocking location, is the train identityregistry apparatus, which is normally located some distance in approachto the interlocking. A train is symbolically shown as approaching thereceiving and registry location, the dottedsymbol being designated bythe reference V. This train or other type vehicle is provided with twoidentity coils for the two digit train identity number specificallyillustrated here. Each of these coils is selectively tuned by a variablecapacitance to one of a preselected number of frequencies. The coil VCT,mounted in such a manner as to precede the other coil VCU as the trainmoves in a normal direction, designates the tens digit of the trainidentity number. Obviously then, coil VCU designates, by its selectedcharacteristic frequency tuning, the unit digit number of the trainidentity.

A typical arrangement for selecting the frequency characteristic of thetrain carried identity coils is shown at the lower left of the samedrawing sheet in FIG. 1A. It is to be noted that, although FIG. 1A showsbut a single typical train coil VC, an equivalent arrangement isprovided for each of the train carried coils, that is, one for eachdigit of the train identity number. For each coil, a manually operablecoil tuning selector switch CTS is provided having an OFF position andten numbered positions designated to 9, inclusive. When the switch CTSis positioned at any one of the numbered positions, a predeterminedamount of capacitance is connected across the coil VC to establish thepredetermined frequency tuning which designates the selected digitnumber. Obviously the circuits may be so arranged that variouscapacitors provided are connected in parallel by certain switchpositions to provide the necessary tuning capacitance without having alarge number of separate capacitors. The showing in FIG. 1A is typicalfor each coil carried on a train and each switch CTS is positioned bythe train operator, or by a carman at the train origin, to establish theselected train identity number.

Immediately in advance of the symbol for train V is a track section AT,which is insulated from the remainder of the stretch of track byinsulated joints conventionally shown. Within the insulated section ATare mounted two coils TC and RC of the wayside receiving apparatus. CoilTC is the transmitter coil and coil RC is the receiver coil which areassociated with the wayside amplifier and receiver, shown here byconventional block and in somewhat more detail in the referenced FIG. 3.However, such train identification receiving apparatus is known in theart and that used in the system of our invention may be similar to thatdisclosed in U.S. Pat. No. 2,753,550, issued to R. W. Treharne on July3, 1956 or the somewhat similar apparatus disclosed in U.S. Pat. No.2,828,480, issued to L. R. Golladay on Mar. 25, 1958. For this reasononly such details of the amplifier and receiver ap paratus are shown inFIG. 3, to be later described, as are absolutely necessary for anunderstanding of the present arrangement. Reference is made to either ofthe cited patents for a full understanding and showing of such receiverapparatus. The wayside coils TC and RC are so mounted as to be in closeproximity to, and thus in inductive relationship with, each of the traincarried coils as the vehicle passes through section AT.

It is to be noted that section AT is provided with a track circuit todetect its occupancy by passing trains. This track circuit apparatus isshown very conventionally since any type of track circuit apparatusknown in the signaling art may be used. Track relay ATR, together withthe other apparatus now herein shown, is so connected to the rails ofthe section that it will be energized and in its picked up position whenno train is occupying any portion of track section AT. When a trainoccupies this track section, relay ATR is deenergized and releases. Afront contact repeater relay ATP is provided which is normally energizedby the obvious circuit connected between terminals B and N of the directcurrent source and ineluding front contact {2 of relay ATR. A similarswitch track section and track circuit are provided at the interlockinglocation shown in the upper right of FIG. 1. The track section WT isoutlined by insulated joints shown by conventional symbols, a trackportion of each of the three possible routes being included in the tracksection. Track relay WTR is provided to detect the occupancy of anyportion of this switch track section by a train. Again, the trackcircuit arrangement is shown very conventionally but, as will beunderstood, relay WTR is energized and picked up when no train isoccupying the interlocking track circuit and will release when a trainoccupies the section. A front contact repeater relay WTP is provided,energized over a simple circuit including front contact I; of relay WTR.As indicated by the downward pointing arrow drawn through its contactarmature, relay WTP has slow release characteristics so that this frontcontact a remains closed for a predetermined time period after the relaywinding is deenergized. The operation of such track circuits and trackrelays and repeaters are so well known in the signaling art that furtherdetail is not given in this specification.

As will be explained in detail later in connection with F IGS. 3 and 4,when train V traverses section AT, the passage of train coils VCT andVCU in succession over wayside coils TC and RC actuates the reception ofthe train identity number by the receiver apparatus. In turn, bothdigits of the train identification are registered in the registryapparatus. At this location, the train identity in decimal form may bedisplayed visually as indicated by the conventional block designated asthe train identity display. Also, during registry, the trainidentification information is translated into the aforementioned 2/5code form and then transmitted over the communication channel to the bitrelays block at the interlocking location. From the bit relays, thetrain identification data is stored in the initial or first storagebank. When any or all other preceding trains have cleared theinterlocking, this train identity information is then transferred intothe final storage bank. Although intermediate banks are not here shownfor simplicitys sake, additional intervening storage banks may beprovided to transfer the train identity one step at a time whilepreceding trains clear the interlocking. When the train identity data isreceived and stored in the final storage bank, it is used to select aroute predetermined for the destination, type, or class of traindesignated by the identity number. The route interlocking apparatus,such systems being known in the art, then controls the establishment ofthe selected route, all safety factors being taken into account by suchinterlocking control systems. It may be desirable also to provide avisual display of the train identification number, as indicated by aconventional dotted block so designated, at the interlocking location.However, due to similarity with other visual displays, no specificcircuits for this second display arrangement are shown in the detaileddrawings. It will be noted that when the train clears section AT at thereceiver and registry location, the sequential response of relays ATRand ATP as they pick up in succession provides energy to reset theregistration apparatus. Similarily, when a train clears section WT atthe interlocking, the sequential response of relays WTR and WTP clearsthe identity storage from the final bank to make way for the transfer ofa similar identification for a following train. These reset andclearance operations of the bit relays and the train identities aredescribed in detail later.

Reference is now made to the detailed circuits and apparatus of theinventive arrangement as illustrated in FIGS. 3 to 6 when these drawingsare physically positioned in the arrangement illustrated in FIG. 2.Across the top of FIG. 3 is shown a portion of the track stretch fromFIG. 1 including track section AT. At the left, in dotted outline form,is the train or vehicle V which has mounted thereon the two coils VCTand VCU which are varibly tuned to predetermined frequencies toestablish the two-digit train identification number. Again, as in FIG.1, the wayside or track coils TC and RC are shown as mounted between therails of section AT to inductively couple with the train carried coilsduring passage of the train through section AT. Track relay ATR and itsrepeater relay ATP are also shown in this figure of the drawing forconvenience.

The wayside receiving apparatus includes an amplifier unit, a series offilters 0 to 9, each tuned to a frequency corresponding to the frequencyestablished by the similarly numbered position of each train carriedswitch CTS, and a filter MF which is tuned to respond to each of the tenpossible frequencies to which the train coils may be tuned. Associatedwith each filter unit is a receiver relay designated as relay MF, or asrelays R0 to R9, each associated with its correspondingly designatedfilter. Each filter is designed to energize its associated relay whenthe frequency characteristic of the received signal is the same as thatfrequency to which the filter is tuned. Since this apparatus is of thetype shown in the previously cited Treharne patent, except thatadditional units are used to correspond with the number of frequenciesemployed, a detailed description is not needed. The apparatus disclosedin the cited Golladay patent may also be adapted for use, if desired.Briefly describing the operation of the receiver apparatus, the passageof each tuned train coil VC to couple with wayside coils TC and RCprovides a received signal having the frequency characteristic of thetrain coil. This signal is passed through a single one of the filters 0to 9 and causes the corresponding relay R0 to R9 to be energized andpick up. Of course, all frequencies are passed by filter MF to energizethe corresponding relay MF. Therefore the operation of relay MF detectsthe passage of each track carried coil, that is, the passage of eachcoil representing a specific digit of the train identification number.Thus the response of this relay may be used to assure the properregistration of the train identity digits.

Since relays R0 to R9 function in an identical manner, except fordistinguishing between the received signal frequency during the passageof each train coil, a half-step arrangement including relays X, Y, and Zis provided to operate in conjunction with relay MF to separate thesuccessive digits of the train identity number as they are sequentiallyreceived from the passing train. Relay X is a two-winding relay of thebiased type, as indicated by the small arrow shown within the symbol foreach relay winding. The use of this type relay is preferable in order toassure that the relay will initially pick up during the relatively briefoperating time of relay MP in response to the passage of the first traincoil. Each of the relays Y and Z are of the magnetic stick type, asindicated by the arrow shown within each winding of these two-windingrelays and by illustrating the contact armatures of these relays in thevertical position. Such magnetic stick relays respond to brief pulses ofenergizing current and operate their contact armatures to the left ornormal position when the conventional flow of energizing current througheither winding is in the direction of the arrow shown within thatwinding. These relays operate their contacts to close in the reverse orright hand position when the conventional current flow opposes thearrow. In either case, the relay contacts remain in the position towhich last operated when energizing current is removed from bothwindings.

Each winding of relay X is provided with an energizing circuit, that forthe upper winding being traced from terminal B over back contact a ofrelay MF and, in multiple, reverse contacts a of relays Y and Z throughthe upper winding of relay X to terminal N. A very simple circuit existsfor the lower winding of relay X which includes only front contact c ofrelay MF. The closing of either of these energizing circuits will causerelay X to pick up its contacts. The energizing circuit for the upperwinding of relay Y includes front contact 0 of relay MF, reverse contact0 of relay Z, and the upper winding of relay Y. When this circuit iscompleted, relay Y is so energized as to operate its contacts to closein their normal position. The circuit for the lower winding of relay Yalso includes front contact c of relay MF but is traced over normalcontact 0 of relay Z and through the lower winding of relay Y in adirection opposite to the arrow shown therein. Obviously, when thiscircuit is completed, relay Y is so energized as to close its contactsin their reverse position. The circuit for the lower winding of relay Zis traced from terminal B over front contact b of relay X, back contactb of relay MF, normal contact c of relay Y, and the lower winding ofrelay Z to terminal N. The conventional flow of current when thiscircuit is completed is in the direction of the arrow in the lowerwinding so that relay 2, thus energized, operates to close its contactsin the normal position. The circuit for the upper winding of relay Z isidentical with that just traced for the lower winding except forincluding reverse contact 0 of relay Y and thence through the upperwinding of relay Z to terminal N. Since the conventional flow of currentin this circuit will be opposite to the direction of the arrow in theupper winding, energization under this situation will cause relay Z toclose its contacts in their reverse position.

In describing the operation of this half-step relay arrangement, it isto be noted that, as shown in the drawing, the relays are in theirat-rest positions which they occupy when all of the train carried coilsof a train have passed over wayside coils TC and RC and moved beyondsection AT, although the train need not necessarily have completelycleared the track section. When a train first enters section AT, so thatits coil VCT comes into inductive relationship with coils TC and RC,relay MF responds to this detection of the train coil and picks up. Theclosing of front contact 0 of relay MF obviously energizes the lowerwinding of relay X which immediately picks up. The lower winding ofrelay Y is also energized over front contact c of relay MF since contact0 of relay Z is presently in its normal position. Relay Y, thusenergized by conventional current of opposing flow, operates itscontacts to close in the reverse position. With relays X and MF pickedup and relay Y in its reverse position, energy is then supplied to thewire bus 11 by a circuit traced from terminal B over front contact b ofrelay X, front contact b of relay MF, reverse contact b of relay Y, andnormal contact b of relay Z. As will be shortly described, the supply ofenergy from terminal B to bus 11 causes the tens digit of the trainidentity, registered temporarily in decimal form by relays R to R9, tobe translated into a 2/5 code form and registered in a bit relay bank.

When coil VCT of this train clears the wayside coils, relay MF respondsby releasing. The opening of front contact b of relay MF obviouslyinterrupts the circuit to bus 11 which is thus deenergized. The closingof back contact a of relay MF, with reverse contact a of relay Y alreadyclosed, completes a holding circuit for relay X through its upperwinding. This circuit is effective before relay X can release due to theopening of front contact c of relay MF. At this time, the upper windingof relay 2 is energized over the circuit including front contact b ofrelay X, back contact b of relay MF, and reverse contact c of relay Y.The conventional flow of current in this circuit opposes the arrow inthe upper winding and relay Z operates its contacts to their reverseposition.

When the second or units digit coil VCU of the train comes intoinductive relationship with the wayside coils, relay MP is againenergized and picks up. This reenergizes the lower winding of relay Xquickly enough that this relay remains picked up, even though its upperwinding is now deenergized. With contact c of relay 2 closed in itsreverse position, the closing of front contact c of relay MF alsoenergizes the upper winding of relay Y, the current flow being such asto cause this relay to operate its contacts to their normal position.Energy is now supplied from terminal B to bus 12 over the circuitincluding front contact b of relay X, and contact b of relay MF, reversecontact b of relay 2, and normal contact b of relay Y. As will beshortly described, this supply of energy on bus 12 translates the unitsdigit presently registered in decimal form into a 2/5 code form in amanner similar to that already accomplished for the tens digit.

When coil VCU clears the wayside coils, relay MF again releases. Theclosing of back contact a of relay MF again provides holding energy tothe upper winding of relay X, this time the circuit including reversecontact a of relay Z. However, the closing of back contact b of relay MFprovides energy from front contact b of relay X over normal contact 0 ofrelay Y to the lower winding of relay Z. Conventional current flow issuch as to cause this relay to operate its contacts to their normalposition. The opening of reverse contact a of relay Z deenergizes relayX and, since front contact c of relay MP is already open, both windingsof relay X are deenergized and it immediately releases. Bus 12 is alsodeenergized when front contact b of relay MF opens. The relays X, Y, andZ are now returned to their usual, at-rest positions as illustrated inthe drawings. It is to be noted that the closing of back contact a ofrelay X supplies energy to a bus wire 13 which is used at this time totransmit the train identity code in its 2/5 form to the advance locationover the communication channel. This will be described shortly. However,it will be obvious that the transmission of the train identity code tothe advance location, here the interlocking location, does not occuruntil the train identity is full registered.

The diode matrix shown at the bottom of FIG. 3 translates the trainidentity from decimal form to the two-out-of-five code form used in therest of the arrangement. This diode matrix is controlled by contacts ofthe R relays which, of course, successively receive each digit of thetrain identity in decimal form. The circuits through the R relaycontacts and the corresponding diodes control the application of energyto the 2/5 code bit relay banks shown in FIG. 4. The upper bank of bitrelays B1 to B5 register the tens digit code while relays B6 to B10register the associated units digit code. Each of these bit relays is ofthe magnetic stick type previously defined. As will appear, contacts aof the R relays control the translation of the tens digit while contactsb of the R relays control the translation of the units digit. Eachtranslation occurs as the corresponding bus lead 11 or 12 is energizedby the half-step relay arrangement.

If it is assumed that the tens digit received is the number 1,registered by relay R1, the circuit for translating this decimal numberinto the equivalent 2/5 code may be traced from bus 11 over frontcontact a of relay R1 and, in multiple, through the two associateddiodes and thence in multiple over leads 14 and 16 to the lowerwindings, respectively, of relays B1 and B3. Since the conventionalcurrent flow in each of these circuits is in the direction of the arrowin the lower winding of the relay, both relays B1 and B3 are properlyenergized to operate their contacts to close in the normal position. Thediodes are used principally to prevent sneak circuits from being set upduring the translation process. Now assuming that the units digit of thetrain identity is registered as the decimal number 5 by relay R5, thecorresponding translation circuits may be traced from bus 12 over frontcontact b of relay R5 and thence in multiple over the associated diodesand leads 20 and 22 to, respectively, the lower windings of relays B7and B9. Again, the current flow is proper so that these relays operateto close their contacts in a normal position. When the leads 1] and 12are deenergized, and thus the lower windings of these bit relays, theactuated contacts are held in the normal position to which they havebeen operated until the relays are later reset, this being acharacteristic of the magnetic stick type relay. This registers the 2/5code bits until they can be transferred over the communication channelto the storage banks at the interlocking location. It should be notedthat a principal characteristic of the 2/5 code format for each identitydigit is that two code bits are on (B relay normal) while the otherthree hits are off (B relay reverse). Said another way, in each digitcode, two bits have a 1 value and the other three bits a 0 value. Noother combination provides a proper code format and this characteristicis later used to check correct transmission.

When the corresponding train completely clears section AT so that trackrelay ATR is again energized and picks up, and prior to the subsequentpickup of repeater relay ATP, a circuit is completed from terminal Bover front contact a of relay ATR and back contact a of relay ATP, lead24, and, in multiple, through the upper windings of all of the bitrelays B1 to B10, inclusive, to terminal N. Since the flow of current inthese upper windings is opposite the direction of the arrows showntherein, such of these relays that are positioned normal will be reset,operating their contacts to close in the reverse position. This preparesthe bit relays at the registry location for accepting the identity coderegistration for the next train.

For simplicity in the schematic circuit layout of the drawings, we havechosen to illustrate the readout of the train identity into a visualdisplay panel in connection with the bit registry relays of FIG. 4. Thetrain identity display panel outlined in dot-dash rectangle in the upperright of FIG. 4 includes ten lights for each digit of the trainidentity. Thus two columns are shown, one for the tens digit and theother for the units digit, each with ten lamps designated by thereference E with a prefix numeral corresponding to the decimal numberwhich that lamp represents. It will be obvious that such display panelsmay be provided in the arrangement wherever desired if a readout fromcode bit relays is available. For example, it is to be noted that such adisplay may be provided at the interlocking location as designated bythe dotted rectangle identified as a train identity display shown at theright of FIG. 1 below the final storage bank. Each such panel will becontrolled by a translation readout from the 2/5 code bit registry orstorage. For example, using the assumed train identity 15, lamp 10E inthe panel of FIG. 4 is energized, while the identity code for that trainis registered in the bit relays of that figure, by a circuit extendingfrom terminal B over normal contact a of relay B1, normal contact a ofrelay B3, and through the filament of lamp 10E to terminal N. Acorresponding circuit for lamp SE of the unit column extends fromterminal B over reverse contact a of relay B6, normal contact b of relayB7, normal contact b of relay B9, and the filament of lamp SE toterminal N. Thus lamps 10E and 5E will be illuminated to indicate thatthe train identity registered is 15. Similar circuits for the otherdisplay lamps may be traced as desired by reference to the drawing andthe above description of the circuits for lamps 10E and 5E.

Upon completion of the registry of all the digits of the train identity,here two digits, the code format is transferred to the remote locationover a communication system, that is, from the registry banks of FIG. 4to the interlocking location shown in FIGS. and 6. It is obvious thatthe 2/5 bit code may be transmitted by any type of remote control systemor other communication channel which is suitable for handling digitaldata. Various types of such systems are well known in the art and theiruse would be understood by those so skilled. For example, a time coderelay system or a solid state code control system would be suitable. Butfor simplicitys sake in the present schematic diagram, the communicationsystem is illustrated as a cable 25, one end of which is shown in thebottom of FIG. 4 and the other in FIG. 5. This cable, for example,includes at least the wires necessary to transmit the 2/5 code bits. Thevarious terminals of these wires, where they fan out from the cable ateach end to relay contacts or windings, respectively, are designated bythe references 31 to 40, inclu- SlVe.

When the train identity registration is complete, at thereceiver-registry location, the code is transmitted over the cable bythe application of energy through selected ones of wires 31 to 40 to thebit storage relays B-A at the remote location, shown in column at theleft of FIG. 5. As previously described, when the half-step relayarrangement returns to its at-rest condition at the end of the receptionand registration of a train identity code, energy is supplied fromterminal B over back contact a of relay X to lead 13, which is connectedin multiple to contacts d of the registry relays of FIG. 4. Using thepresent example, with the train identity number registered, normalcontacts d of relays B1, B3, B7, and B9 are closed. Thus energy isapplied to terminals 31, 33, 37, and 39 of the cable wires and flowsthrough the cable to the corresponding terminals at the left of FIG. 5and thence through the windings of the bit storage relays BlA, B3A, B7A,and B9A, respectively. It is to be noted that, if a cable is actuallyused as the communication channel, an additional lead is necessary toprovide a connection to terminal N of the energy source provided at theidentity registration location of FIGS. 3 and 4 so that the right handterminals of relays B-A may be connected to the corresponding negativeterminal of their energy source. Such matters are within the limits ofsystem design, however, and need not be discussed in more detail here.It is also to be noted that, after energy is reapplied to lead 13 at theend of an identity registration, i. e., when relay X releases, thetransmission of the registered 2/5 code format from relays B to relaysB-A over the communication channel cable 25 is continuous until thattrain clears section AT and relays B are reset, as previously described.

At the remote or interlocking location, two relay storage banks for the2/5 code bits received from the registry location are provided. Thefirst or initial bank includes various storage relays 28, each with asuffix number corresponding to the bit position or number in the codeformat. The final storage bank includes the storage relays 1S, each witha suffix also corresponding to the number of the bit in the code format.Obviously other intervening banks may be provided as necessary betweenthese initial and final storage banks shown. The requirement is thatthere must be sufficient banks to store the train identity code for eachtrain which can possibly occupy the track stretch between thereceiver-registry location of FIG. 3 and the interlocking location ofFIG. 6. One particular element of this requirement is that at least theinitial bank must be empty and prepared to accept a storage immediatelyfor any train permitted to pass the registry location, i. e., sectionAT, and enter the stretch. This is true since, as will become evidentshortly, the bit code transmitted over the communication channel intothe BA relays of FIG. 5 must immediately transfer into the initial banksince the bit relays are not provided with any holding circuit.

Each bank includes a storage repeater relay or relays, for example,relay 2SP associated with the initial bank and relays ISP and 18??associated with the final bank. The SP relay in each case repeats thestorage of any train identity code within the bank and must be in itsreleased condition to allow a new code to transfer into thecorresponding bank. For example, the energizing circuit for relay ZSPincludes, in multiple, front contact 0 of each of the storage relays 251to 2510, inclusive. The stick circuit for relay 25? includes, inmultiple, front contact b of each bit registry relay BIA to 810A, frontcontact a and the winding of relay ZSP completing the stick arrangement.Relay ISP is provided with a back contact repeater relay ISPP which isnormally energized over back contact b of relay 15?. The energizingcircuit of relay 18? includes front contacts c, in multiple, of storagerelays 1S1 to 1810 of the final storage bank, front contact a of relayISPP, and the winding of relay 18?. The stick circuit for relay 1SPsubstitutes its own front contact a to bypass front contact a of relay15?? in the energizing circuit. Relay lSPP has slow releasecharacteristics, which is indicated by the downward pointing arrow drawnthrough the movable portion or armature of each of its contacts. Itshould be noted that, if intermediate storage banks are provided, theenergizing and stick circuits for the SP relay associated with each suchbank are similar to those just described for the final bank relay 18?.The stick circuit for relay 2SP differs from that for other banks andincludes contacts of the bit relays so that no second transfer of thesame identity code registered in bit relays BIA to B10A can occur intothe initial bank in case the code storage immediately cascades forwardinto other storage banks. Thus as long as a code bit registry remains inrelays 31A to B10A, a second transfer can not occur into the initialstorage bank relays 281 to 2810. Back contact repeaters such as relayISPP are provided for each intermediate storage bank also but are notnecessary for the initial storage bank.

Assuming that the train identity code for train number 15 is transmittedover the communication channel into relays BIA, B3A, B7A, and 89A aspreviously described, this code is transferred into the initial storagebank relays having the same suffix numbers. For example, a circuitexists from terminal B over back contact 12 of relay ZSP, a diode, frontcontact a of relay BIA, the winding of relay 251, and either backcontact 0 of relay 1SP or back contact a of relay ISPP to terminal N.Similar circuits may be traced for relays 283, 257, and 289 overmultiple circuits including, respectively, front contacts a of relaysB3A, B7A, and B9A, the connections to the right terminal of each storagerelay winding being connected to the common circuit over contacts 0 ofrelays ISP and ISPP. As each storage relay 28 picks up, it completes astick circuit for itself over its own front contact a further includingthe corresponding relay winding and back contact c of relay ISP or lSPP.If the final bank in this case already contains a code storage, backcontact c of relay ISPP will be closed to complete the energizing andstick circuits. Back contact c of relay 18? will close to retain thestick circuits when this final bank becomes clear of a code storage. Asthe storage in the initial bank is transferred forward so that relay ISPis again energized and picks up to open its back contact 0, the stickcircuit for the 2S storage relays will be interrupted since relay lSPP,with its slow release characteristics, will retain its back contact 0open for a sufficient period to allow release of the storage relays 28.

When the final storage bank is empty so that relay 18? is released andits repeater ISP? is again picked up, a circuit network is completed fortransferring the code storage from the initial bank into the final bank.These circuits extend from terminal B at front contact b of relay 18??over back contact d of relay lSP, front contact 0 of relay 28?,indicating that a storage exists in the initial bank, thence in multiplethrough circuit paths including a diode and front contact b of eachrelay 28 which is picked up and the winding of the correspondinglynumbered relay 1S, and finally over front contact a of relay WTP or backcontact a of relay WTR to terminal N. The last two relays were discussedin connection with the illustration in FIG. 1 and the relay windingsymbols are here shown dotted as the control circuit for each relaywinding is shown in FIG. 1. Under the assumed condition that the trainidentity code stored represents the number 15, relays 151, 183, 187, and1S9 are energized when this transfer from the initial to the finalstorage bank occurs since the similarly numbered relays 28 are pickedup. The stick circuit for relay 181 under these conditions includes itsown front contact a, the relay winding, and either back contact a ofrelay WTR or front contact a of relay WTP. It will be noted thatinitially front contact a of relay WTP is used to complete theconnection to terminal N since this storage transfer only occurs whenthe interlocking arrangement is clear of a train. Back contact a ofrelay WTR will close to retain the code storage in the final bank whenthe corresponding train has accepted the established route and movesthrough the interlocking track circuit. Since relay WTP has a slowrelease characteristic, its front contact a will remain closed untilafter back contact a of relay WTR closes. When the train clears sectionWT, back contact a of relay WTR opens before front contact a of relayWTP closes. This interrupts the stick circuits for all energized relays18, which then release to cancel the identity code storage.

For purposes of clarity in the drawings, we have chosen to use repeatersof the 1S storage relays to control the actual route selection matrix.These are the train identity relays T shown across the top of FIG. 6.Each T relay repeats the 1S relay having a similar suffix numeral and isenergized over a simple front contact circuit controlled by contact b ofthe corresponding lS relay. Each circuit extends through cable 26between the identically numbered cable terminals. Thus relay T1 repeatsrelay 181 over the circuit including from contact b of relay 1S] andextending between terminals 41 of cable 26 through the winding of relayT1. Each T relay thus registers a bit of the 2/5 train identity codewhich has been transmitted from the registry location and cascadedthrough the storage relay banks. In keeping with the previouslydiscussed characteristics of the 2/5 code format, a T relay registers acode bit 1 value when picked up and a code bit value when in itsreleased condition.

This use of repeater relays will allow the storage banks to be mountedoutside the interlocking control machine and the T relay bank, togetherwith the U relays shortly discussed, to be mounted at or in the machine.It also permits the use ofa simpler type relay with multi-contactstructure as needed for the checking, translation, and route selectionmatrices. However, any visual display of the train identity provided atthe interlocking location will be controlled directly by the 1S storagerelays. The same kind of translation circuitry as used for the displaypanel illustrated in FIG. 4 will be used to control the display lamps.Since the illustration of a second display panel and its controlcircuitry would be redundant, only the single arrangement of FIG. 4 isillustrated herein for simplicity. Also in FIG. 6 is shown a series ofunit digit registry relays U. Each of these relays is further designatedby a numerical sufi'ix which indicates the decimal numeral which thatrelay registers. The control circuit arrangement for these U relaystranslates from the 2/5 code storage into the decimal storage as will beshortly described.

Referring again to FIG. 6, the contact matrix and associated circuitryimmediately below the T relays is a 2/5 code check arrangement for boththe ten and unit digit portion of the train identity code. This checkassures that each digit code, that is, each digit portion of the codeformat, registers only two on or 1 value bits out of the five bits ofthe group for a proper registration of the digit. The check signal isthen passed through other contacts of relays T6 through T10, inclusive,to translate the unit digit code into a decimal format which isregistered in the aforementioned U relay bank. Unless a relay U isenergized, there is no route selection. This assures that both parts ofthe 2/5 code format have been correctly registered and transmitted tothis location. As an example, let us trace the check of the code formatfor the train identity number which has been assumed throughout theprevious discussion. If such a code format is correctly registered,relays T1 and T3 will be energized and picked up to store the tens digitportion while relays T7 and T9 will be picked up to store the unitsdigit portion. As a result of the check and translation operation, relayUS should be energized through the circuit matrix.

Tracing now from terminal 5, the circuit extends over back contact a ofrelay T10, back contact b of relay T8, back contact c of relay T6, fromcontact a of relay T7, front contact a of relay T9, back contact a ofrelay T5, front contact b of relay T3, front contact b of relay T1 backcontact b of relay T2, and back contact a of relay T4 to complete thecode format check. To complete the code translation, the circuit furtherextends over from contacm c of relays T7 and T9 and through the windingof relay U5 to terminal N. The energization of relay US by this tracedcircuit thus assures that a proper 2/5 code format has been registeredand also translates the unit digit portion thereof into decimal form,energizing relay US to indicate that the unit digit is the number 5. Areview of the checking circuit matrix will illustrate that if, in eitherportion of the 2/5 code format, a third relay was energized or only onerelay was energized, this incorrect code registry would have interruptedthe previously traced circuit at some point and relay US would not havebeen energized.

The remaining circuit network in FIG. 6, which includes a matrix ofcontacts of the U relays and front contacts of relays T1, T2, and T3, isa typical route selection circuit network provided as an example only.This circuit network is not exclusive, in our invention, of othercircuitry necessary to select the here available routes or other routesfor other train identity numbers. For example, in the illustratednetwork, trains having identity numbers 01, 04, and 12 will select aroute E, that is, leading from the principal track stretch in theapproach and continuing into track TE shown in the upper right of FIG. 6and also in FIG. 1. The circuit network also provides that trains havingidentity numbers 02, 03, and 10 will select route F while those withidentity numbers 06, 07, and 15 will select route G. Actually, routeselections for other train numbers are also included in the illustratednetwork but sufficient examples have been given. It is to be understoodthat other train identity numbers, of the total plurality possible inthe multidigit system here disclosed, will select the same or otherroutes over distinct circuit networks not here shown. For example, thedotted lines also extending from front contact d of relay T1 designateother possible route selection circuits for other train identity numberswhich would include this contact of relay T 1. Other circuit networkswould originate at contacts of other T relays of the group TI to T5 asrequired.

As a particular example, let us trace the route selection circuit forthe train identity number 15 that has been used in the previousexamples. The circuit extends from terminal B at front contact d ofrelay Tl, which is closed, over fronteontact c of relay T3, frontcontact a of relay U5, and through the winding of route selection relayG to terminal N. Relay G is thus energized by this circuit and picks upto select a route into track TG for the approaching train having theidentity number 15. The energization and pickup of relay G together withan indication of the approach of train number 15 will actuate the routecontrol apparatus of the interlocking control system to establish theroute from the approach track into track TG, operating the switches andclearing the signals as safety conditions permit to allow this train tomove along the interlocking route into track TG. The operation of thisinterlocking control system will be understood by those skilled in theart and additional details of its operation need not be illustrated ordiscussed herein since such is not a specific part of our invention.

Summarizing now the previous description of the detailed circuits inFIGS. 3 to 6 as an operational description, let us assume that a trainwith the identity number 15 approaches track section AT shown in FIG. 3.The switch CTS for coil VCT on this train is set in its number 1position to establish the tens digit at 1 while the corresponding switchfor train coil VCU is set at its position 5 to establish the units digitat 5. The setting of these two switches tunes the corresponding traincarried coils to the selected frequency for these decimal numbers. Trackrelay ATR followed by its repeater relay ATP sequentially release as thetrain occupies track section AT. However, since front contact a of relayATR opens first, prior to the closing of back contact a of relay ATP, noenergy is applied at this time to wire lead 24. As coil VCT passes overwayside coils TC and RC, relays MF and R1 of the receiver apparatus pickup. Relay R1, of course, establishes the characteristic of the receivedsignal, that is, the frequency tone representing the digit signal indecimal form. As previously described, the pickup of relay MF actuatesrelay X to pick up and relay Y to operate to its reverse position sothat energy from terminal B is applied to bus 11. With relay R1 alsopicked up, energy from bus 11 is further applied through front contact aof relay R1 and the corresponding multiple circuits through the diodesto leads 14 and 16. This in turn energizes bit relays B1 and B3 shown inupper left of FIG. 4. These relays operate to close their contacts intheir normal position. As coil VCT passes out of its inductiverelationship with the wayside coils, relays MF and R1 release, causingrelay Z to operate to its reverse position. However, as previouslynoted, relay X is held in its picked up position at this time. Energy isremoved from bus 11 so that no further transfer of any information tobit relays B1 to B5 can occur.

Coil VCU then passes over wayside coils TC and RC. Relay MF again picksup together with relay R5. Relay Y at this time operates to its usualnormal position so that energy is supplied to bus 12. With relay R5picked up to close its front contact b, energy from bus 12 flows throughthe associated diodes to leads 20 and 22 which in turn energizes relaysB7 and B9 in a manner to close their contacts in the normal position.When train coil VCU clears the wayside coils, relay MF again releasestogether with relay R5. Relay Z operates to its normal position andrelay X subsequently releases, restoring the halfstep relay arrangementto its at-rest condition. Bus 12 is also deenergized, but now relays B1,B3, B7, and B9 hold in their normal position due to the characteristicof the magnetic stick type relay. Eventually, when the train itselfcompletely clears section AT so that track relay ATR picks up, energy isapplied to wire lead 24 to reset all relays B1 to B to their usualreverse positions. However, prior to this time the forward transmissionof the train identity information has occured.

With normal contacts a of relays B1 and B3 closed, energy is applied tolamp 10E of the train identity display panel so that this lamp isilluminated. Similarly, with reverse contact a of relay B6 closed andnormal contacts b of relays B7 and B9 closed, energy is also applied tolamp SE which is likewise illuminated so that the train identity displaypanel indicates that the passing train has the identity 15. When relay Xreleases to close its back contact 0 energy is supplied to wire lead 13,which action occurs prior to the reset of the bit relays of FIG. 4. Thisenergy from lead 13 is applied over normal contacts a of relays B1, B3,B7 and B9 to, respectively, terminals 31, 33, 37, and 39 of cable 25.This energy flows over the communication channel, illustrated by cable25, to energize the auxiliary bit relays BIA, B3A, B7A, and 39A on FIG.5. Thus the train identity registration is now transmitted to theinterlocking location which is in advance along the stretch of trackfrom the position of the approaching train.

If a sufficient number of storage banks have been provided, relay 28? ofthe initial storage bank will be in its released position so that energyis available over its back contact b and over front contacts a of theenergized auxiliary bit relays to energize relays 281, 253, 2S7, and 289of the initial storage bank. These relays, thus energized, pick up andclose their front contacts a to complete a stick circuit for each relay,which further 1 unique stick circuit arrangement prevents a secondtransfer of the same train identity information into the initial storagebank in case the information is immediately cascaded forward to otherstorage banks, since with back contact b of relay 28? held open, noentry of an identity storage into the initial bank can occur. If thesecond or final storage bank illustrated here already contains astorage, the stick circuits to hold the storage in the initial bankinclude back contact 0 of relay ISPP. However, if no storage exists inthe final bank, so that back contact c of relay ISP is closed, the stickcircuit is completed over this connection.

If or when the final storage bank is free of any storage so that relayISP is released and relay lSPP is picked up, a circuit is completed overfront contact b of relay lSPP, back contact d of relay ISP, and frontcontact c of relay 281 (closed with a storage in the initial bank) totransfer this existing storage into the final bank, the multiplecircuits also including from con tacts b of whichever 2S relays areenergized. Under the presently described conditions, circuits arecompleted to energize relays 1S1, 183, 187, and 189 since thecorrespondingly numbered relays of the initial bank are picked up. Thistransfers the storage identity 15 into the final bank. The energizedstorage relays 18 complete stick circuits, over their own front contactsa, further including from contact a of relay WTP which is closed at thistime since any preceding train has now cleared the interlocking area.When the train whose storage is now in the final bank, as indicated bythe picked up condition of selected 18 relays, enters the interlockingarea over the selected route, relay WTR will release to close its backcontact a to complete a second and alternate connection for the stickcircuit which remains closed until the train clears the interlockingtrack circuit. Thus a train identity storage in the final bank can notbe cancelled until the corresponding train has completely cleared theinterlocking area along its selected route.

When this storage transfers into the final storage bank, relay ISP isenergized over its circuit including front contacts 6, in multiple, ofwhichever 1S relays are picked up and front contact a of repeater relaylSPP. Relay ISP is held energized over a stick circuit including its ownfront contact a and front contacts c of the energized storage relays.When back contact c of relay lSP opens and prior to the closing of backcontact 0 of relay lSPP, which is held open for a selected period by theslow release characteristics of this later relay, the stick circuits forthe energized storage relays in the initial bank are interrupted. Thetrain storage held therein is thus cancelled, having been cascadedforward into the final bank prior to this time. With back contact d ofrelay 18? now open, any subsequent storage for a following train can notbe transferred into the final bank on top of the storage held thereinand the separation of the train identity information is maintained.

The train identity storage now held in the final bank, that is, the 1Srelay storage bank, is repeated by the train identity relays T in theroute selection network of FIG. 6. In the present example, energy issupplied to relays T1, T3, T7, and T9 over front contacts b of,respectively, relays 181, 183, 187, and 189 and cable leads 41, 43, 47,and 49 of cable 26. When the train identity is registered in the Trelays as indicated, the code check circuit network and the units digittranslation network check the proper format of the 2/5 code received andtranslate the units digit back to decimal form. For example, with thetrain identity code 15 now stored in the T relays, the previously tracedcircuit is completed for checking the code and translating the unitsdigit. The code checking portion includes back contacts a, b, and c ofrelays T10, T8, and T6, respectively, front contacts a of relays T7 andT9, back contact a of relay T5, front contacts b of relays T3 and T1,and back contacts b and a of, respectively, relays T2 and T4, while thetranslation portion includes front contacts 0 of relays T7 and T9 andthe winding of relay U5. Since each half of the code format checkingnetwork indicates that only two of the possible five relays are pickedup so that proper format exists, the unit digit is then translated sothat relay U5 is energized.

As previously explained, if in either half of the 2/5 code format, thatis, in the relay groups T1 to T5 and T6 to T10, less than or more thantwo relays are picked up, the translation network is incomplete and unitrelay US will not be energized. In other words, if less than or morethan two 1 bits are registered for either digit, the unit digittranslation can not occur. Thus the energization of a unit relay, totranslate that portion of the train identity multi-digit code, indicatesthat the original 215 code format has proper characteristics.

The route selection circuit network at the bottom of FIG. 6 now selectsthe route for the train in accordance with the registered trainidentity, here assumed to be the number 15. The circuit networkillustrated is so designed that the train identity 15 selects a routefrom the approach track to track TG so that route selection relay G mustbe energized. This circuit includes front contacts d of relay T1 and cof relay T3 and then over front contact a of relay U5 to the winding ofrelay G so that this later relay is energized and picks up to select theproper route. If, for another example, the train identity registered inthe T relays had been the number 08, the illustrated route selectionnetwork will select route relay E for energization. Under theseconditions, the circuit includes front contact a' of relay T1 and frontcontact 0 of relay T2, which are closed to indicate a tens digit ofzero, and thence over front contact a of relay U8 to the winding ofrelay E. If desired, the code format check circuit completed at thistime to energize relay U8 may be traced, remembering that, for a proper2/5 code format registration, relays T1 and T2 must be picked up for thetens digit and relays T8 and T10 picked up for the units digit. If thetrain identity number is 10, so that relays T1 and T3 and, if the codeformat is proper, relay U0 are picked up, a circuit exists for selectingrelay F including front contact a of relay T1, front contact c of relayT3, and front contact a of relay U0. Other route selection circuits maybe traced if desired. For example, such train identity numbers as 04,05, and 13 will, respectively, cause the selection of relays E, F, andG. The specific tracing of additional circuits appears to be redundantin view of the preceding descriptions and further details will not beincluded.

When any one of the three illustrated route selection relays E, F, or Ghas been energized, the route control apparatus of the interlockingcontrol system is actuated to establish the desired route. For the trainidentity number 15 used in the principal example herein, the routecontrol apparatus will operate the switches shown conventionally toroute the train from the approach track over the two switches into trackTO. A very simple interlocking arrangement has been shown in order toillustrate the arrangement of our invention, but the control of a morecomplicated track arrangement by similar interlocking apparatus and theselection of the necessary routes therein in accordance with theregistered train identity will be obvious when taken in connection withthe accompanying drawings and the preceding description.

The arrangement of our invention thus provides a convenient and straightforward means of receiving, registering, and transmitting to an advancelocation a multi-cligit train identity signal. This identity signal maybe used as a function control signal to actuate a wayside identitydisplay or, preferably, to select a route through an interlocking andactuate the establishment of such a route prior to the arrival of thecorresponding train. This, of course, conserves train time and thusincreases its average speed of travel by reducing the delays which mayoccur at a station location due to passenger hesitancy as to traindestination or delays resulting from the inability of an operator to setup interlocking routes sufficiently in advance of train arrival. Thesystem provides a maximum of one hundred different train identities, butis not limited to such a complete system and may be used to handle asmaller number of different identities. Under these conditions, theamount of apparatus provided is reduced to only that required. A checkis also provided of the registry of the proper code format for a trainidentity at the final location. Utilization of an incorrect code forselecting an improper control function, for example, an improper route,is thereby prevented. An efiicient and economical system is thusprovided for controlling a wayside function for an approaching tram.

Although we have herein shown and described but one form of anarrangement embodying our invention for controlling a wayside functionin accordance with an identity control signal transmitted fromapproaching trains, further changes and modifications may be madetherein within the scope of the appended claims without departing fromthe spirit and scope of our invention.

Having thus described our invention, what we claim is:

1. Apparatus for controlling from a train a wayside function locatedalong the stretch of track traversed by that train, comprising incombination,

a. a plurality of coils on said train, each preset to a selected one ofa plurality of possible signal characteristics and mounted in apredetermined relationship with the other coils to represent apredetermined digit of a multi-digit function control signal,

b. receiver apparatus positioned to couple with each train coil formomentarily recording each digit of said function control signal indecimal form during passage of the corresponding train coil inaccordance with its selected signal characteristic,

c. a bank of code registry relays for each digit of said functioncontrol signal,

d. translation means controlled by said receiver apparatus andresponsive to the passage of each train coil for successivelytranslating the corresponding recorded digit decimal signals intopreselected code formats and connected for registering each digit signalcode format in the corresponding digit bank of said code registryrelays, and

e. function control means for operating the wayside function to acondition determined by the digit characteristics of the registeredfunction control signal,

f. said code registry relay banks connected for controlling saidfunction control means in accordance with the signal characteristicsrepresented by each digit of the registered function control signalcode.

2. Function control apparatus as defined in claim 1 in which saidreceiver apparatus comprises,

a. a pair of coils mounted along said track for coupling with eachtrain-carried coil,

b. a plurality of receiver relays, one for each of said possible signalcharacteristics, each controlled by said track coils to receive thecorresponding characteristic signal from said train coils, and

c. stepping means responsive to the successive passage of said traincoils for actuating the translation and registration of eachcharacteristic signal received by said receiver relays into thecorresponding digit bank of registry relays.

3. Function control apparatus as defined in claim 2 in which said traincoils are mounted to couple with said track coils successively indescending order of the digits of said function control signal.

4. Function control apparatus as defined in claim 3, further including,

a. a communication means controlled in part by said registry relays fortransmitting said function control signal code from the location of saidtrack coils to a remote location where the wayside function is located,

b. said function control means connected to said communication means toreceive the signal code format from said registry relays and responsivethereto for operating said wayside function.

5. Function control apparatus as defined in claim 4 in which,

a. the selected signal characteristic of each train coil is a signalfrequency to which the coil is selectively tuned.

b. each receiver relay is frequency coupled to said track coils torespond only to a predetermined different one of said signal frequenciesto which said train coils may be tuned.

6. Function control apparatus as defined in claim 5, in which thewayside function is the route selection for a route type interlockingcontrol system to establish a route through an interlocking tracknetwork for a train from an approach track to an exit trackpredetermined by the selected route, said track coil location beingalong the approach track stretch, and in which said function controlmeans includes,

a. a plurality of storage relays connected to said communication meansfor receiving and storing a function control signal code transmittedfrom said track coil location,

b. a route selection circuit arrangement controlled by said storagerelays for checking the proper code format of the stored control signaland for selecting a desired route through said interlocking inaccordance with the characteristics of the stored control signal only ifthe code format is proper.

7. Function control apparatus as defined in claim 1 in which saidfunction control means comprises,

a. a bank of route selection relays, one for each of plurality of routesthrough a track interlocking network traversed by trains first passingsaid receiver apparatus, each relay when selected actuating theestablishment of the corresponding track route through saidinterlocking,

b. a route selection circuit network controlled by said registry relaybanks for selecting a single route selection relay in accordance withthe signal characteristics of a function control signal code registeredin said registry relay banks, and

c. a code check circuit network also controlled by said registry relaybanks for completing the selection of the single route relay only whenthe registered function control signal code format has the proper codecharacteristics.

8. A multi-digit train identity control system for a stretch of tracktraversed by trains, comprising in combination,

a. a plurality of coils on each train mounted in sequence so that eachcoil represents a predetermined one of the train identity signal digits,each coil selectively tuned to one of a plurality of differentfrequencies to establish a predetermined value for the correspondingdigit of the train identity signal,

b. wayside coils positioned along said track to inductively couple witheach train-carried coil during passage of the corresponding train forreceiving a separate frequency signal in accordance with the frequencytuning of each train coil,

c. a bank of receiver relays, each frequency coupled to said waysidecoils to receive a predetermined one of said frequency signals from saidtrain coils for recording the value of each train identity signal digitin decimal form,

d. stepping means also coupled to respond to the passage of each traincoil for recording the sequence of the identity signal digits,

e. a bank of registry relays for each identity signal digit,

f. translation circuit means controlled by said receiver relays and saidstepping means for successively translating each digit signal recordedby said receiver relays into a predetermined code format and connectedfor registering the signal code format in the registry relay bankcorresponding to the identity digit recorded at that time by saidstepping means, and

g. control means connected for receiving each train identity signalregistered by said registry relay banks and responsive thereto forconditioning a controllable wayside function associated with thecorresponding train to a condition defined by said registered identitysignal code.

9. A train identity control system as defined in claim 8, in which saidcontrollable function is the route selection for a route control systemfor a track interlocking network at a location remote from and latertraversed by trains first passing said wayside coils, furthercomprising,

a. a communication means controlled by said registry relays andresponsive to the registration of a train identity signal code fortransmitting that code to said remote location of said controllablefunction, I b. storage means at said remote location with connecuons forreceiving and storing a train identity signal code transmitted over saidcommunication means, and

c. a route selection means for said route control system controlled bysaid storage means for selecting a track route through said interlockingin accordance with the stored train identity signal code and foractuating said route control system to establish the selected route.

10. A train identity control system as defined in claim 9 in which saidroute selection means includes,

a. a route selection relay for each route through said trackinterlocking network,

b. a code checking circuit matrix including contacts controlled by saidstorage means for checking the proper code format of each digit of astored train identity signal code,

. a decoding circuit network including other contacts controlled by saidstorage means for establishing a route selecting circuit path for thetrain identified by the stored identity signal code, and

d. at least one energizing circuit for each route selection relayincluding in series a circuit path through said code checking circuitmatrix and a circuit path through said decoding circuit networkcorresponding to the identity signal code for a train preselected tofollow the interlocking route established by that route selection relay,

. a particular energizing circuit being completed only when a properidentity signal code format is stored and the thereby identified trainis preselected to follow the route corresponding to the associated routeselection relay.

11. A train identity control system as defined in claim 9 in which saidcode format is of the two-out-of-five type and in which a circuit paththrough said code checking circuit matrix is completed only when two oncode bits only are stored for each digit of the train identity signalcode.

1. Apparatus for controlling from a train a wayside function locatedalong the stretch of track traversed by that train, comprising incombination, a. a plurality of coils on said train, each preset to aselected one of a plurality of possible signal characteristics andmounted in a predetermined relationship with the other coils torepresent a predetermined digit of a multi-digit function controlsignal, b. receiver apparatus positioned to couple with each train coilfor momentarily recording each digit of said function control signal indecimal form during passage of the corresponding train coil inaccordance with its selected signal characteristic, c. a bank of coderegistry relays for each digit of said function control signal, d.translation means controlled by said receiver apparatus and responsiveto the passage of each train coil for successively translating thecorresponding recorded digit decimal signals into preselected codeformats and connected for registering each digit signal code format inthe corresponding digit bank of said code registry relays, and e.function control means for operating the wayside function to a conditiondetermined by the digit characteristics of the registered functioncontrol signal, f. said code registry relay banks connected forcontrolling said function control means in accordance with the signalcharacteristics represented by each digit of the registered functioncontrol signal code.
 2. Function control apparatus as defined in claim 1in which said receiver apparatus comprises, a. a pair of coils mountedalong said track for coupling with each train-carried coil, b. aplurality of receiver relays, one for each of said possible signalcharacteristics, each controlled by said track coils to receive thecorresponding characteristic signal from said train coils, and c.stepping means responsive to the successive passage of said train coilsfor actuating the translation and registration of each characteristicsignal received by said receiver relays into the corresponding digitbank of registry relays.
 3. Function control apparatus as defined inclaim 2 in which said train coils are mounted to couple with said trackcoils successively in descending order of the digits of said functioncontrol signal.
 4. Function control apparatus as defined in claim 3,further including, a. a communication means controlled in part by saidregistry relays for transmitting said function control signal code fromthe location of said track coils to a remote location where the waysidefunction is located, b. said function control means connected to saidcommunication means to receive the signal code format from said registryrelays and responsive thereto for operating said wayside function. 5.Function control apparatus as defined in claim 4 in which, a. theselected signal characteristic of each train coil is a signal frequencyto which the coil is selectively tuned. b. each receiver relay isfrequency coupled to said track coils to respond only to a predetermineddifferent one of said signal frequencies to which said train coils maybe tuned.
 6. Function control apparatus as defined in claim 5, in whichthe wayside function is the route selection for a route typeinterlocking control system to establish a route through an interlockingtrack network for a train from an approach track to an exit trackpredetermined by the selected route, said track coil location beingalong the approach track stretch, and in which said function controlmeans includes, a. a plurality of storage relays connected to saidcommunication means for receiving and storing a function control signalcode transmitted from said track coil location, b. a route selectioncircuit arrangement controlled by said storage relays for checking theproper code format of the stored control signal and for selecting adesired route through said interlocking in accordance with thecharacteristics of the stored control signal only if the code format isproper.
 7. Function control apparatus as defined in claim 1 in whichsaid function control means comprises, a. a bank of route selectionrelays, one for each of plurality of routes through a track interlockingnetwork traversed by trains first passing said receiver apparatus, eachrelay when selected actuating the establishment of the correspondingtrack route through said interlocking, b. a route selection circuitnetwork controlled by said registry relay banks for selecting a singleroute selection relay in accordance with the signal characteristics of afunction control signal code registered in said registry relay banks,and c. a code check circuit network also controlled by said registryrelay banks for completing the selection of the single route relay onlywhen the registered function control signal code format has the propercode characteristics.
 8. A multi-digit train identity control system fora stretch of track traversed by trains, comprising in combination, a. aplurality of coils on each train mounted in sequence so that each coilrepresents a predetermined one of the train identity signal digits, eachcoil selectively tuned to one of a plurality of different frequencies toestablish a predetermined value for the corresponding digit of the trainidentity signal, b. wayside coils positioned along said track toinductively couple with each train-carried coil during passage of thecorresponding train for receiving a separate frequency signal inaccordance with the frequency tuning of each train coil, c. a bank ofreceiver relays, each frequency coupled to said wayside coils to receivea predetermineD one of said frequency signals from said train coils forrecording the value of each train identity signal digit in decimal form,d. stepping means also coupled to respond to the passage of each traincoil for recording the sequence of the identity signal digits, e. a bankof registry relays for each identity signal digit, f. translationcircuit means controlled by said receiver relays and said stepping meansfor successively translating each digit signal recorded by said receiverrelays into a predetermined code format and connected for registeringthe signal code format in the registry relay bank corresponding to theidentity digit recorded at that time by said stepping means, and g.control means connected for receiving each train identity signalregistered by said registry relay banks and responsive thereto forconditioning a controllable wayside function associated with thecorresponding train to a condition defined by said registered identitysignal code.
 9. A train identity control system as defined in claim 8,in which said controllable function is the route selection for a routecontrol system for a track interlocking network at a location remotefrom and later traversed by trains first passing said wayside coils,further comprising, a. a communication means controlled by said registryrelays and responsive to the registration of a train identity signalcode for transmitting that code to said remote location of saidcontrollable function, b. storage means at said remote location withconnections for receiving and storing a train identity signal codetransmitted over said communication means, and c. a route selectionmeans for said route control system controlled by said storage means forselecting a track route through said interlocking in accordance with thestored train identity signal code and for actuating said route controlsystem to establish the selected route.
 10. A train identity controlsystem as defined in claim 9 in which said route selection meansincludes, a. a route selection relay for each route through said trackinterlocking network, b. a code checking circuit matrix includingcontacts controlled by said storage means for checking the proper codeformat of each digit of a stored train identity signal code, c. adecoding circuit network including other contacts controlled by saidstorage means for establishing a route selecting circuit path for thetrain identified by the stored identity signal code, and d. at least oneenergizing circuit for each route selection relay including in series acircuit path through said code checking circuit matrix and a circuitpath through said decoding circuit network corresponding to the identitysignal code for a train preselected to follow the interlocking routeestablished by that route selection relay, e. a particular energizingcircuit being completed only when a proper identity signal code formatis stored and the thereby identified train is preselected to follow theroute corresponding to the associated route selection relay.
 11. A trainidentity control system as defined in claim 9 in which said code formatis of the two-out-of-five type and in which a circuit path through saidcode checking circuit matrix is completed only when two on code bitsonly are stored for each digit of the train identity signal code.